diff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt index 63fd7cfa4cf1..e6b72d355151 100644 --- a/Documentation/device-mapper/cache.txt +++ b/Documentation/device-mapper/cache.txt @@ -221,7 +221,7 @@ Status <#used cache blocks>/<#total cache blocks> <#read hits> <#read misses> <#write hits> <#write misses> <#demotions> <#promotions> <#dirty> <#features> * -<#core args> * <#policy args> * +<#core args> * <#policy args> * metadata block size : Fixed block size for each metadata block in sectors @@ -250,6 +250,7 @@ feature args : 'writethrough' (optional) #core args : Number of core arguments (must be even) core args : Key/value pairs for tuning the core e.g. migration_threshold +policy name : Name of the policy #policy args : Number of policy arguments to follow (must be even) policy args : Key/value pairs e.g. sequential_threshold diff --git a/drivers/md/dm-cache-policy-mq.c b/drivers/md/dm-cache-policy-mq.c index e63e36cefc89..930e8c3d73e9 100644 --- a/drivers/md/dm-cache-policy-mq.c +++ b/drivers/md/dm-cache-policy-mq.c @@ -1276,7 +1276,8 @@ static struct dm_cache_policy_type default_policy_type = { .version = {1, 2, 0}, .hint_size = 4, .owner = THIS_MODULE, - .create = mq_create + .create = mq_create, + .real = &mq_policy_type }; static int __init mq_init(void) diff --git a/drivers/md/dm-cache-policy.c b/drivers/md/dm-cache-policy.c index d80057968407..c1a3cee99b44 100644 --- a/drivers/md/dm-cache-policy.c +++ b/drivers/md/dm-cache-policy.c @@ -146,6 +146,10 @@ const char *dm_cache_policy_get_name(struct dm_cache_policy *p) { struct dm_cache_policy_type *t = p->private; + /* if t->real is set then an alias was used (e.g. "default") */ + if (t->real) + return t->real->name; + return t->name; } EXPORT_SYMBOL_GPL(dm_cache_policy_get_name); diff --git a/drivers/md/dm-cache-policy.h b/drivers/md/dm-cache-policy.h index 052c00a84a5c..f50fe360c546 100644 --- a/drivers/md/dm-cache-policy.h +++ b/drivers/md/dm-cache-policy.h @@ -222,6 +222,12 @@ struct dm_cache_policy_type { char name[CACHE_POLICY_NAME_SIZE]; unsigned version[CACHE_POLICY_VERSION_SIZE]; + /* + * For use by an alias dm_cache_policy_type to point to the + * real dm_cache_policy_type. + */ + struct dm_cache_policy_type *real; + /* * Policies may store a hint for each each cache block. * Currently the size of this hint must be 0 or 4 bytes but we diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 11ad70540d40..09334c275c79 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -2832,7 +2832,7 @@ static void cache_resume(struct dm_target *ti) * <#demotions> <#promotions> <#dirty> * <#features> * * <#core args> - * <#policy args> * + * <#policy args> * */ static void cache_status(struct dm_target *ti, status_type_t type, unsigned status_flags, char *result, unsigned maxlen) @@ -2900,6 +2900,8 @@ static void cache_status(struct dm_target *ti, status_type_t type, } DMEMIT("2 migration_threshold %llu ", (unsigned long long) cache->migration_threshold); + + DMEMIT("%s ", dm_cache_policy_get_name(cache->policy)); if (sz < maxlen) { r = policy_emit_config_values(cache->policy, result + sz, maxlen - sz); if (r)